Progressive senescence programs induce intrinsic vulnerability to aging-related female breast cancer

Cancer incidence escalates exponentially with advancing age; however, the underlying mechanism remains unclear. In this study, we build a chronological molecular clock at single-cell transcription level with a mammary stem cell-enriched population to depict physiological aging dynamics in female mice. We find that the mammary aging process is asynchronous and progressive, initiated by an early senescence program, succeeded by an entropic late senescence program with elevated cancer associated pathways, vulnerable to cancer predisposition. The transition towards senescence program is governed by a stem cell factor Bcl11b, loss of which accelerates mammary ageing with enhanced DMBA-induced tumor formation. We have identified a drug TPCA-1 that can rejuvenate mammary cells and significantly reduce aging-related cancer incidence. Our findings establish a molecular portrait of progressive mammary cell aging and elucidate the transcriptional regulatory network bridging mammary aging and cancer predisposition, which has potential implications for the management of cancer prevalence in the aged.

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Shang Cai
Apr 2, 2, 2024 Whole mount images were obtained using a stereomicroscope (Nikon, SMZ18).Western blot imaged by by Gel imaging system (GE, AI680RGB) Luciferase activity results were tested using the microplate reader (Thermo, Varioskan LUX).Flow cytometrhy files were collected using FACS Aria II II (BD Bioscience).Immunohistochemistry and HE HE staining Images were obtained using Eclipse Ti2 inverted microscope (Nikon).scRNA-sequencing results were collected using Illumina novaseq 6000 platform (Novogene).

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We used 25 mice to do the scRNA-seq to make sure we could build the aging trajectory.We used more than 3 mice to test the drug effect.
Low quality scRNA-seq data were excluded.
Each result described in the paper is based on at least two independent biological replicates for animal experiments.Further details are described in each figure legend.
Mice studies: Age and background-matched mice were randomly allocated into the groups for all animal experiments.
We didn't perform blinding for in vivo measurement, as blinding was considered not to affect the measurement result.Other analysis were performed without informing the investigators with the group allocation.
Comma D beta cell line was kindly provided by Dr. Medina.
All cell lines were not authenticated.
All cell lines used in our study were negative for mycoplasma contamination.
No commonly misidentified cell line was used.
This project did not use wild animals.
This study only applied to the mammary glands of female mice.
This project did not involve samples collected from the field.
Animals were housed in a specific pathogen-free conditions and fed standard mouse chow.All animal experiments were carried out in compliance with China laws and regulations.The local institutional animal ethics board (Institutional Animal Care and Use Committee of Westlake University) approved all mouse experiments (permission numbers: 19-001-2-CS).Experiments were performed in accordance with government and institutional guidelines and regulations.All mice are housed at 20-24°C with 40-60% humidity, and 12-h cycle of light/darkness (7a.m. to 7p.m.).
We have already deposited the ChIP-seq data to GEO database under the accession number GSE195647.To review GEO accession GSE195647: Go to https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE195647, enter token wxmhkmaqvtmxpqr into the box.